"The United States will never, never, never recognise Russia's claim on Ukraine sovereign territory," US President Joe Biden said on Thursday, while UN Secretary General António Guterres had already said the annexation "would have no legal value and deserves to be condemned".

But that still leaves the question: what now? How will Mr Putin respond when Ukrainian troops push on to try to reclaim their land?

Russia has already warned that any attack on its "new territories" will be viewed as an attack on the territorial integrity of Russia. The Kremlin says it reserves the right to respond "with all means available to it".

That includes, potentially, nuclear weapons. In recent weeks, senior Russian officials have been dropping unsubtle hints about Moscow's nuclear arsenal.

In his speech today, Vladimir Putin said the United States had created a "precedent" by using nuclear weapons against Japan at the end of World War Two.

That comment won't have gone unnoticed by Western governments.

Russia's nuclear sabre-rattling has been causing concern in the West. But it's worrying people inside Russia, too. This week, an editorial in the country's mainstream Nezavisimaya Gazeta newspaper was heavily critical of "senior Russian officials" for making "nuclear threats".

"It is incredible that today… high-ranking officials in Russia start talking about the nuclear button," the editorial continued. "They do this without a second thought… They even forget to make the qualification so important for the world to hear: 'Of course, we mustn't allow this under any circumstance.'

"To allow, in thoughts and words, the possibility of a nuclear conflict is a sure step to allowing it in reality."

What struck me most about President Putin's annexation speech was just how full it was of anti-Western bile. The Russian president seems set on whipping up nationalistic, anti-Western sentiment in the country.

It's a useful diversion from the problems at home and the battlefields of Ukraine.

BBC